The present invention refers to a method for automatically picking up hosiery articles from a container, in species socks, knee socks, and the like, made of knitted sponge-like cotton, wool, cotton, or synthetic fibres, and for their subsequent loading on automatic finishing lines. Furthermore the invention relates to a device that carries out this method.
In the following description, reference is made to a non-limiting example of socks. However, it should be understood that the same method can be extended to knee socks and other hosiery articles.
In an automatic production cycle, before a hosiery article reaches the final packaging step, it must follow a path with various working steps.
Usually, starting from a step of automatic or manual pick up of the hosiery article from a special container, the sock passes through intermediate steps that provide seaming, and/or steaming, up to the final packaging.
Presently, hosiery articles are picked from special containers manually. Techniques also exist of automatic pick up by means of a feeding sucker that holds the hosiery articles raising them from a special container. This technique, however, is applicable only for veiled articles such as collants, knee socks, and stockings, which are made of thin knitted veil and are very flexible.
On the other hand, the same feeding sucker system does not allow an automatic pick up from a container of other hosiery articles, made of synthetic fibres, but with thicker knitting, as well as in sponge-like cotton, wool, or thick cotton. For such articles, only manual loading systems are presently known.
It is therefore an object of the present invention to provide a method for automatically picking up hosiery articles from a container, in particular socks, knee socks, and the like, knitted of spongy and/or wool material, which overcomes the drawback of the existing techniques.
It is, furthermore, an object of the invention to provide a device that carries out this method.
The pick up method according to the invention provides the use of a grasping device moving from a starting position. The free end of the grasping device, comprising, in one embodiment, grasping jaws, gradually approaches the bulk of hosiery articles gathered in a container. The grasping device is suspended from an end of an actuator, but is not integral to the actuator so that as soon as the jaws of the grasping device contacts the free surface of the bulk of hosiery articles, the actuator continues for a brief additional stroke. In particular, the additional stroke causes the grasping device to contact the hosiery articles without stopping the lowering of the grasping device even after a first contact with the free surface of the bulk of the hosiery articles.
The end of the brief additional stroke, i.e. when the actuator has approached the grasping device, or the beginning of the additional stroke, i.e. when the actuator starts the approaching movement to the grasping device, are detected automatically and it indicates with certainty that the grasping device has met the bulk of hosiery articles in the container. At this point, when it is detected that the support is close to the grasping device, or after having detected the beginning of the approaching movement of the support to the grasping device, the jaws are closed automatically, grasping at least one hosiery article. Then, the whole device, by means of the actuator, is moved from the pick up position to an unloading position. In the unloading position, the jaws release the hosiery article(s) on a loading plane of a finishing machine. Then, the whole device returns to the starting position above the container for another picking up step.
According to another aspect of the invention, a device for automatically picking up one or more hosiery articles from a container comprises:
support integral to the movable part of an actuator;
a grasping device having grasping means;
a sliding guide of said grasping device with respect to said support, wherein said grasping device Is suspended from said support at a predetermined distance from it and can be pushed to approach said support;
proximity sensor means, of the approached position reached by said grasping device with respect to said support;
means for blocking said grasping means responsive to said proximity sensor means, at said approached position.
In one embodiment, the sensor means is comprised of one or more proximity sensors integral to the support that detects the vicinity of the grasping device within a predetermined range. In this case, advantageously, a mechanical pawl is provided that prevents the grasping device from contacting the sensors integral to the actuator.
Alternatively, the sensor means is comprised of proximity sensors integral to the support that detect the passage of the sliding guide with respect to the support. In this case, the contact of the grasping device with the hosiery articles is detected and the device stops the grasping device as it approaches the actuator and is properly positioned relative to the hosiery articles.
In particular, the signals coming from the sensor means cause the closure of the jaws for grasping the hosiery articles. The following opening movement of the jaws is operated by the control unit at the unloading station where the hosiery article is released.
In one embodiment, the grasping means is comprised of a pair of jaws operated by pneumatic means and a control unit which operates the pneumatic means in response to signals coming from the sensor means.
In an alternate embodiment, the grasping device provides a opening adjustment device of the jaws that allows for the adjustment of the maximum opening of the jaws with respect to a longitudinal axis of the device for picking up only one hosiery article at a time.